Astroblog

Obscured by Clouds. The rough and ready blog of a cloud benighted biologist and amateur astronomer. Astroblog will cover my interests in astronomy, biology and Life, the Universe and Everything.

Monday, August 25, 2014

The Sky This Week - Thursday August 28 to Thursday September 4

The First Quarter Moon is Tuesday September 2. Mercury climbs higher in the
evening sky. Mars and Saturn are prominent in the evening sky, forming a nice triangle with Alpha Librae. The trio are visited by the Moon on the 31st and September 1.
This is the last week to see Venus is low in the morning twilight. Jupiter rises higher.

The First Quarter Moon is Tuesday September 2.

Evening
sky on Sunday August 31 looking west as seen from Adelaide at
22:00
(10:00 pm) ACST in South Australia. Mars and Saturn are at their closest under the head of Scorpius.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen).

Mars
is easily seen in the western evening sky, setting just before midnight. Mars was
at opposition, when it
is biggest and brightest, on the 9th of April, and
is still
readily distinguishable as the bright red/orange object above the western horizon in the early evening.

Mars is in the constellation
of Libra. It begins the week forming a triangle with the broad
double star Alpha Librae
(also called Zubenelgenubi) and
Saturn. Over the week it draws away from Saturn, forming a larger triangle. The trio of Mars, Saturn and Alpha Librae are visited by the Moon on August the 31st and September 1.

Saturn
is in the early western evening sky, and was at opposition
on June 11th. Saturn
is visible most of the evening. Saturn is high enough
from twilight for decent telescopic observation for a few hours and sets just before midnight.

Saturn is in Libra near the head
of the constellation of the Scorpion and forms a shallow triangle with
the
two brightest stars of Libra. It also forms a triangle with Alpha Librae
(Zubenelgenubi) and Mars. The trio of Mars, Saturn and Alpha Librae are visited by the Moon on August the 31st and September 1.

Evening
sky on Sunday August 31 looking west as seen from Adelaide at 18:30
(6:30 pm) ACST in South Australia. Mercury is now reasonably high above the horizon in the twilight.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen).

Mercury climbs higher in the evening sky and is now readily visible low
above the western horizon, in the latter twilight. It becomes easier to see during the week.

Morning sky on Sunday August 31 looking north-east as seen from
Adelaide
at 6:15 am ACST. Venus is low above the horizon, Jupiter is above it (click
to embiggen).

Venus
is in the morning sky, low above the north-eastern horizon. Despite its
brightness, it is very difficult to see low in the twilight.

Venus is pulling away from Jupiter, although you will need a clear, level horizon
to see Venus in the twilight glow.

This is the last week to see Venus before it disappears into the glare of the Sun.

Jupiter rises higher in the morning
twilight, and now is fairly easy to see low above the
horizon at twilight. During the week Jupiter climbs higher and becomes easier to see.

There are lots
of interesting things in the sky to view with a telescope. Especially
with Mars and Saturn prominent in the early evening sky. If you don't have a telescope, now
is a good time to visit one of your local astronomical societies open nights or the local planetariums.

Mars, Saturn and Zubenelgenubi close (25-27th August 2014)

Evening
sky on Monday August 25 looking west as seen from Adelaide at
22:00
(10:00 pm) ACST in South Australia. Mars and Saturn are at their closest under the head of Scorpius.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen).

After slowly drawing together Mars and Saturn are at their closest tonight (the 25th) tomorrow night and Wednsday night (the 27th).

Mars and Saturn form a triangle with Alpha Librae
(also called Zubenelgenubi) at this time. Go out tonight or over the next few days and have a look.

Here is an animation of them drawing together from the 18th to the 223rd.

Tuesday, August 19, 2014

The Sky This Week - Thursday August 21 to Thursday August 28

The New Moon is Tuesday August 26. Mercury climbs higher in the
evening sky. The Moon is close to Mercury on the 27th. Mars
and Saturn are
prominent in the evening sky are at their closest this week.
Venus is low in the morning twilight while Jupiter rises higher. The Moon is close to Venus and Jupiter on the 23rd and 24th.

The New Moon is Tuesday August 26. The Moon is at apogee (furthest from the Earth), on the 24th.

Evening
sky on Monday August 25 looking west as seen from Adelaide at
22:00
(10:00 pm) ACST in South Australia. Mars and Saturn are at their closest under the head of Scorpius.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen).

Mars
is easily seen in the western evening sky, setting around midnight. Mars was
at opposition, when it
is biggest and brightest, on the 9th of April, and
is still
readily distinguishable as the bright red/orange object above the western horizon in the early evening.

Mars is in the constellation
of Libra. It begins the week forming a shallow triangle with the broad double star Alpha Librae and
Saturn. Over the week it draws towards Saturn, and is at its closest between the 25th and the 27th. Mars and Saturn form a triangle with Alpha Librae
(also called Zubenelgenubi) at this time.

Saturn
is in the early western evening sky, and was at opposition
on June 11th. Saturn
is visible most of the evening. Saturn is high enough
from twilight for decent telescopic observation for a few hours and sets around midnight.

Saturn is in Libra near the head
of the constellation of the Scorpion and forms a shallow triangle with
the
two brightest stars of Libra. It also forms a shallow triangle with Alpha Librae
(Zubenelgenubi) and Mars. By the 25th to the 27th. Mars and Saturn will
be at their closest.

Evening
sky on Wednesday August 27 looking west as seen from Adelaide at18:30
(6:30 pm) ACST in South Australia. Mercury and the thin Crescent Moon are low above the horizon in the twilight.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen).

Mercury climbs higher in the evening sky while it is low
above the western horizon, it beomes easier to see during the week.

On August 27 the thin crescent Moon visits Mercury

Morning sky on Sunday August 24 looking north-east as seen from
Adelaide
at 6:30 am ACST. Venus is low above the horizon, Jupiter is above it and the thin crescent Moon forms a triangle with them (click
to embiggen).

Venus is in the morning sky, above the north-eastern horizon. Despite its brightness, it is now difficult to see low in the twilight.

Venus is still close to Jupiter, although you will need a clear, level horizon
to see them in the twilight glow.

During the week Venus pulls away from Jupiter as Jupiter rises in the sky and Venus sinks closer to the horizon.

On the 23rd the crescent Moon, Venus and Jupiter form a line. Although low in the twilight, if
you have a flat horizon (like the ocean or dessert), you should be able
to see them (and at least the Moon and Jupiter early on).

On the 24rd the thin crescent Moon, Venus and Jupiter form a triangle. The thin Moon will be quite difficult to see low in the twilight, but again if
you have a flat horizon (like the ocean or dessert), you should be able
to see them. You may need binoculars to see all three in the twilight. Northern Australia has better views than southern Australia.

Jupiter it rises higher in the morning
twilight, but will difficult to see without a clear level
horizon. During the week Jupiter pulls away from Venus. On the 23rd and 24th the crescent Moon lines up with Jupiter and Venus (see details above).

There are lots
of interesting things in the sky to view with a telescope. Especially
with Mars and Saturn prominent in the early evening sky. If you don't have a telescope, now
is a good time to visit one of your local astronomical societies open nights or the local planetariums.

Monday, August 18, 2014

Mars and Saturn, Sunday 17 August, 2014

Mars, Zubenelgenubi and Saturn almost from a line below the head of the Scorpion on Sunday 17 August (three brightest objects mid left, click to embiggen)t. 10 x 15 second exposures at ASA 400 with a "point and shoot" Canon IXUS, stacked in ImageJ, SUMMED an light contrast editing applied.

While the conjunction of Venus and Jupiter was quite good, Mars and Saturn have been slowly approaching each other. They will be closest on the 25th but not as close as Jupiter and Venus were this morning).

Mars, Zubenelgenubi and Saturn actually form a straight line tonight, but cloud got in the way.

Sunday, August 17, 2014

Venus and Jupiter Close together in the Twilight Glow (morning, 18 August 2014)

Morning sky on Monday August 18 looking north-east as seen from
Adelaide
at civil twilight, 6:30 am ACST. Venus is low above the horizon, Jupiter is so close it may be hard to see it separately. The inset shows the binocular view (click to embiggen)

Morning sky on Monday August 18 looking north-east as seen from Brisbane
at civil twilight, 5:22 am AEST. (click to embiggen)

Morning sky on Monday August 18 looking north-east as seen from Darwin
at civil twilight, 6:37 am ACST. (click to embiggen)

This Monday morning (18 August) Venus and Jupiter are less than half a fingerwidth apart and may be difficult to distinguish with the unaided eye. However, this close conjunction is deep in the twilight, and will be difficult to see.

While viewers further north have the best views if you have a flat horizon (like the ocean or dessert),
you should be able to see them if you look half an hour before local sunrise.

From Adelaide the pair are a mere three finger-widths above the horizon at civil twilight (half an hour before sunrise), from Brisbane a hand-span above the horizon at civil twilight and from Darwin a hand-span and a half almost (see diagrams above). From Melbourne and Hobart the pair are even closer to the horizon.

The pair are close enough that the will easily fit into the field of view of standard binoculars. With the advancing dawn, you may need binoculars to even see Jupiter. Be very
careful of the rising sun though.

Readers Rob and Julie Walpole and Chris Wyatt have sent in some great images of the occultation of Saturn on August 4. Rob and Julie sent along their friend Christine Beswick's image of the "near miss" ocultation in Tasmania.Reader Chris Wyatt capture the Moon and Saturn, and the dramatic moment when Saturn just began to pass behind the Moon.

Remeber that copyright invests with them folks, so please ask if you want ot use their pictures.

Tuesday, August 12, 2014

The Sky This Week - Thursday August 14 to Thursday August 21

The Last Quarter Moon is Sunday August 17. Mercury returns to the evening sky late in the week. Mars
and Saturn are
prominent in the evening sky and come closer together during the week. Venus is low in the twilight and meets Jupiter on the 18th.

The Last Quarter Moon is Sunday August 17.

Evening
sky on Thursday August 21 looking north-west as seen from Adelaide at
22:00
(10:00 pm) ACST in South Australia. Mars and Saturn are close together under the head of Scorpius.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen). The inset shows the
telescopic view of Saturn at this time,

Mars
is easily seen in the western evening sky, setting around midnight. Mars was
at opposition, when it
is biggest and brightest, on the 9th of April, and
is still
readily distinguishable as the bright red/orange object above the western horizon in the early evening.

Mars is now in the constellation
of Libra forming a line with the broad double star Alpha Librae and Saturn. Over the week it draws towards Saturn and Alpha Librae, and is very close by the 21st. Mars will be at its closest to Saturn next week.

Saturn
is in the early north-western evening sky, and was at opposition
on June 11th. Saturn
is visible most of the evening. Saturn is high enough
from twilight for decent telescopic observation and sets shortly after midnight.

Saturn is in Libra near the head
of the constellation of the Scorpion and forms a shallow triangle with the
two brightest stars of Libra. It also forms a line with Alpha Librae (also called Zubenelgenubi ) and Mars. By the 21st Mars and Saturn will be close.

Morning sky on Monday August 18 looking north-east as seen from
Adelaide
at 6:30 am ACST. Venus is low above the horizon, Jupiter is so close it may be hard to see it separately.

The inset shows a simulation of the binocular view of these two worlds. Similar
views will be seen
throughout
Australia at equivalent
local times. (click
to embiggen).

Venus is in the morning sky, above the north-eastern horizon. The brightest object
in the early morning sky, it is rapidly heading towards horizon, and becomes more difficult to see the twilight.

Venus was at its furthest distance from
the Sun on the 23rd of March, and is now rapidly sinking further into the twilight, becoming quite difficult to see. During the week Venus comes closer to Jupiter, although you will need a clear, level horizon to see them in the twilight glow.

On the 18th Venus and Jupiter are at their closest, and may be difficult to distinguish with the unaided eye. Although low in the twilight, if you have a flat horizon (like the ocean or dessert), you should be able to see them close together in binoculars. Be very careful of the rising sun though.

Jupiter it rises higher in the morning
twilight, but will difficult to see without a clear level
horizon. During the week Jupiter comes closer to Venus.

Mercury returns to the evening sky by the end of the week, and can be seen low above the western horizon, it will become more prominent next week..

There are lots
of interesting things in the sky to view with a telescope. Especially
with Mars and Saturn prominent in the early evening sky. If you don't have a telescope, now
is a good time to visit one of your local astronomical societies open nights or the local planetariums.

Monday, August 11, 2014

Images of the 10 August 2014 "supermoon"

The so-called "supermoon" of tonight (August 10/11) was very beautiful, but with the unaided eye I couldn't tell it apart from previous Full Moons.

However, it was very obvious in the telescope, even at 8:30 pm the Moon was obviously bigger than January's "mini-Moon" (aphelion Full Moon). The top image shows tonights Moon on the left at 8:30 pm, and the mini-Moon of January on the right. Click on the image to embiggen.

The bottom image shows the Moon at 10:30 pm (still 5anda half hours from maximum approach and largest apparent diameter) on the left, and January's "mini Moon" on the right. The size difference is glaringly obvious.The position of the Maria and craters is slightly different in each image due to libration.

Another way to do this is to glue half of the image from today (top) to half from January (bottom), this makes it slightly clearer. The images are at exactly the same scale. (click to embiggen)

The top images have been processed to increase contrast, but are otherwise untouched.

So, pretty good night. If you got some pictures tonight, but don't have any from January, you have to wait until March 5th in 2015 for a comparable Mini Moon.

Saturday, August 09, 2014

Australian Perseid Meteor Shower - Morning August 13, 2014

Perseid radiant as seen from Darwin at 5:00 am local time, August the 13th, looking north.

Perseid radiant as seen from Brisbane at 5:00 am local time, August the 13th, looking north. Note how much lower the radiant is.

The Perseid Meteor Shower
runs from July 17–August 24, and peaks on the morning of Wednesday August 13 between 11 am-2:00 pm AEST (00h to 03h on August 13 UT).
Despite this being a quite
reasonable meteor shower in the northern hemisphere, for most
of Australia the radiant is below the horizon, and only the very
occasional meteor will be seen shooting up from the northern horizon.

This year is particularly bad, not only does the peak occur after sunrise, but the nearly full Moon is not far from the radiant on the best nights.

Anyone
south of Brisbane will see only the occasional meteor, say maybe one
or two per hour (or less), the further north of Brisbane you are, the more
meteors you will see.

You can check predictions for your local area at the NASA meteor flux estimator (choose 7 Perseids and 12-13 August 2014). People around the latitude
of Darwin have the best chance of seeing meteors, possibly as many as
one every 10 minutes at the peak (see table below). Next is places with
the latitude of Cairns, then with the latitude of Mackay (like Port
Headland and Mt Isa), and the places with the latitude of Alice Springs
(again,see table below).

To see the meteors, you will need to be up from around 3:00 am
local time on the 13th (yes, a really horrible hour of the morning),
with best views 4:00 am-5:30 am. The meteor shower will be located due
North, with the radiant just above the northern horizon. Cloud cover predictions can be found at SkippySky.

When you get up, allow at least 5 minutes for your eyes to adjust, and
be patient, it may be several minutes before you are rewarded with you
first meteor, then a couple will come along in quick succession. Choose a
viewing spot where you can see a large swathe of sky without trees or
buildings getting in the way, or with streetlights getting in your eyes.
The darker the spot the better (but do be sensible, don't choose a spot
in an unsalubrious park for example).

A lawn chair or something similar
will make your observing comfortable (or a picnic rug spread on the
ground and a nice pillow), and having a Thermos of hot coffee, tea or
chocolate to swig while watching will increase your comfort. (Here's
some
hints on dark adaption of your eyes so you can see meteors better).

UPDATE: for some reason the original table edits failed, and last years rates went out. This is now fixed.

The following table show the peak rates at around 5 am local time on the
mornings of the 12th, 13 and 14th of August for a number of cities under dark sky conditions.
Rates will be similar at the same latitude as these cities, and rates
will be intermediate at spots between these cities.

Town

Morning August 12

Morning August 13

Morning August 14

Alice Springs

3 meteors/hr

4 meteors/hr

3 meteors/hr

Brisbane

2 meteors/hr

2 meteors/hr

2 meteors/hr

Cairns

5 meteors/hr

7 meteors/hr

6 meteors/hr

Darwin

6 meteors/hr

9 meteors/hr

8 meteors/hr

Mackay

4 meteors/hr

5 meteors/hr

5 meteors/hr

Note, those of you who have Stellarium, in version 13 they have added meteor shower radiants (rates set in the planets dialogue, F4). However the Perseids don't seem to work from Australia.

Friday, August 08, 2014

The "Super Moon" of Sunday August 10/ Monday August 11, What Can You See?

Illustration of the orbit of the Moon around the Earth. Distances for apogee and perigee are given for the 2011 Full Moons because I was lazy and didn't want to redraw the diagram.

The Full Moon of this Monday August 11 occurs at perigee.
Actually, it is a little tricky. Full Moon is 18:09 August 10 UT, which is 04:09 August 11 AEST (03:39 ACST).

Yes, the Full Moon and perigee occurs in the early morning of August 11, if you wait until Moon rise on the evening of the 11th, it will all be over.

If you don't feel like staying up until 3am, then around 10-11 pm on Sunday the 10th will do just fine (see below).

Some folks have started to call perigeean Full Moons "Super Moons" for reasons that, to my mind, are not entirely justified. Still, we have the name, let's move on. What will you see, and what are the implications of this coming "Super Moon".

The
Moon has an elliptical orbit around the Earth (greatly exaggerated for
illustrative purposes in the diagram above). When the Moon is
closest to Earth, it is at perigee, and furthest, at apogee. The orbit
of the Moon precesses around the Earth, so that sometimes perigee occurs
at full Moon, sometimes at new Moon, and every time in between. Also
for a variety of reasons the distances of closest and furthest approach
can vary by up to almost 1,000 Km.

Perigee Full Moons ("super moons") are closer and brighter than other full Moons.

So, what can you see?

Without a telescope, and a near photographic memory, not much. This years perigee full Moon
could appear up around 17% bigger and around 30% brighter in the
sky than this years apogee Moon.

However, the full Moon is only around half a finger-width wide in the sky, 17% of half a finger-width is not very much.

Technically the Moon is around 33 arc minutes wide (33'). The limit of distances that someone
with good vision can distinguish between is 1 minute of arc (about the
width of a human hair). So, for the vast majority of people any
difference smaller than 1 minute of arc cannot be seen.

Comparison of the January 16 mini Moon and the August 11 "Super" Moon simulated in Stellarium. With the unaided eye, the Moon
only appears half a finger-width wide, so the difference is much harder
to see.

On Jan 16th, the Moon was 406536 Km from Earth at furthest remove, while
on August 11 it will be 356896 Km away at closest approach at 3 am.

At 11 am on the 10th (a more reasonable hour) the Moon will be 356926.2 Km away.

While the effect is really obvious in a telescope, visually it is very
hard to see the difference even if you have fantastic eyesight. On
January the 16th 2014, the apogee diameter was 29'32", for the perigee
Moon of August 11 at 3 am it will be 33'90". At the more reasonable hour of 11 pm on the 10th it will be 33'56".

In both cases the Moon is around half
the width of your finger, and 4' (that's minutes of arc, about 4 human
hairs in width) different. This is around the limit of what humans can
distinguish. If you have great eyesight and and a great memory you will
be able to distinguish between the January and August full Moons, but otherwise, no.

However, it
will be a good photo opportunity, if you have a decent zoom on your
camera or access to a small telescope. If you have not already taken an image on January 16 (see here for mine), taking a photo of the Moon on August 10 and then again on March 5th in 2015 you will see a decent difference (you need to use exactly the
same
zoom enlargement, see Inconstant Moon for instructions).

For a list of full/new Moons and the dates of apogee/perigee see here.

What will Happen?

The Moon will be bright and lovely, if lucky you may see a satellite pass or a meteor (sadly, there appear to be no International Space Station passes or Iridium flares at this time). Maybe you may see a Moon Bow. But nothing else will happen.

Wednesday, August 06, 2014

Latest Images of Comet 67P from the arrival of Rosetta

Arrival image (screen capture) click to embiggen

close up of end of comet

Arrival image just from the press conference on the science of Rosetta and 67P, just downloaded and processed, also an end image, unfortunately I accidental overwrote the activity image and some other close-ups. The image scale is 2.5 meters per pixel.

Tuesday, August 05, 2014

The Sky This Week - Thursday August 7 to Thursday August 14

The Full Moon is Monday August 11. This is a perigee Moon (a so-called "super Moon"). Mars
and Saturn are
prominent in the evening sky. Venus is low in the twilight. Perseid meteor shower August 12-13.

The Full Moon is Monday August 11. This is a perigee Moon, when the Moon
is closest to the Earth. Perigee Full Moons have been called a "Super
Moons".

Comparison of the January 16 mini Moon and the August 11 "Super" Moon simulated in Stellarium.

While a perigee Full Moon is bigger and brighter than the average Full Moon, this is imperceptible to the unaided eye (and even with a telescope you will need a good memory or photographic evidence to see the difference.

On Jan 16th, the Moon was 406536 Km from Earth at furthest remove, while
on August 11 it will be 356896 Km away at closest approach. See here and here for more information.

Evening
sky on Saturday August 9 looking north-west as seen from Adelaide at
22:00
(10:00 pm) ACST in South Australia. Spica, Mars and Saturn form a line pointing at Scorpious.
Similar views will be seen elsewhere
at the equivalent local time (click to embiggen). The inset shows the
telescopic view of Saturn at this time,

Mars
is easily seen in the north-western evening sky.
It is highest in the sky around 17:30, setting after midnight. Mars was
at opposition, when it
is biggest and brightest, on the 9th of April, and
is still
readily distinguishable as the bright red/orange object above the
north-western horizon in the early evening. Mars is in the constellation
of
Virgo in between the bright star Spica and Saturn. Over the week it draws away
from Spica heading towards Saturn.

Saturn is high in the early north-western evening sky, and was at opposition on June 11th. Saturn
is visible most of the evening. Saturn is high enough
from around 7 pm for decent telescopic observation and sets around 1:00 am. Saturn is in Libra near the head
of the constellation of the Scorpion and forms a line with the
two brightest stars of Libra. It also forms a line with Spica and Mars, which points to the head of Scorpius, the Scorpion. On the 10th Saturn will be excellent in telescopes as it has a prominent ring shadow across its surface.

Morning sky on Sunday August 10 looking north-east as seen from
Adelaide
at 6:30 am ACST. Venus is low above the horizon. Similar
views will be seen
throughout
Australia at equivalent
local times. (click
to embiggen).

Venus is in the morning sky, above the north-eastern horizon. The brightest object
in the early morning sky, it is rapidly heading towards horizon, and becomes more difficult to see the twilight.

Venus was at its furthest distance from
the Sun on the 23rd of March, and is now rapidly sinking towards
the horizon. Venus
forms a triangle bright red star
Betelgeuse and the bright star Procyon.
During the week Venus comes closer to the horizon, although still readily visible in the twilight.

Jupiter
is lost in the
twilight. Towards the end of the week it rises higher in the morning twilight, but will be near impossible to see without a clear level horizon

Perseid radiant as seen from Darwin at 5:00 am local time, August the 13th, looking north.

The Perseid Meteor Shower
peaks on the morning of Wednesday
August 13 between 11 am-2:00 pm AEST (00h
to 03h on
August 13 UT).

Despite this being a quite
reasonable meteor shower in the Northern Hemisphere, for most
of Australia and a large chunk of the Southern Hemisphere the radiant is below the horizon, and only the very
occasional meteor will be seen shooting up from the northern horizon.

Basically, anywhere south of the latitude of Brisbane (27.3 degrees
South) will see few, if any, meteors under ideal conditions. This year with the Full Moon so close to the peak, and the peak occurring during local daylight hours, the chance of anywhere in Australia seeing decent Perseids is negligible.

There are lots
of interesting things in the sky to view with a telescope. Especially
with Mars and Saturn so prominent in the sky. If you don't have a telescope, now
is a good time to visit one of your local astronomical societies open nights or the local planetariums.

Reminder, with added cities, Occultation of Saturn by the Moon 4 August, 2014

The Moon as seen from Darwin at Saturn ingress (20:05 ACST) and exit (21:19 ACST). Similar views will be seen at similar latitudes (Broome Weipa, Townsville, Cairns). Click to
embiggen.

The Moon as seen from Alice Springs at Saturn ingress (20:10 ACST) and exit
(21:40 ACST). Similar views will be seen at similar latitudes (eg. Carnarvon, Longreach, Rockhampton). Click to
embiggen.

The Moon as seen from Adelaide at Saturn ingress (20:30 ACST) and exit
(21:28 ACST). Similar views will be seen at similar latitudes (eg. Perth, Canberra, Sydney). Click to
embiggen.

The Moon as seen from Melbourne at Saturn ingress (21:24 AEST) and exit
(21:52 AEST). Similar views will be seen at similar latitudes (eg. Albany, Warrnambool, Orbost). Click to
embiggen.

Just a reminder that on the evening of Monday 4 August Saturn is occulted by the Moon as
seen from the most of Australia. This is the
third and best of these rare occultations, it is under reasonable dark
skies, with Saturn slipping behind the dark limb of the Last Quarter
Moon. Saturn reappears while the Moon is still reasonably high. See here and here for images of the May 14 occulation.

The occultation occurs in the early evening with the Moon will be
reasonably high above the north west horizon, a good time to show the
kids this event (see below for a table of times). The Moon is easily visible and a ready signpost to Saturn.

The images above show the location of Saturn as it goes behind, then exits the Moon at some representative sites. Basically, the further North you are, the further towards the Moons north pole Saturn enters and exits.

Of course, if you don't readily know where the north pole is, this is confusing. Basically the north pole of the Moon is where all the dark "seas" are that make the face of "the Man in the Moon", the south pole is the bright end.

Saturn slowly slides behind the Moon as seen from Warrnambool at 20:56 AEST.

While everywhere except Tasmania sees Saturn go behind the Moon (Tasmanians get to see Titan scrape along the edge of the Moon which will be cool too), the most dramatic views will be in Southern Victoria, where the Moon slides along the edge of the Moon before vanishing, then reappears sliding from behind the lighted side of the Moon.

Although this event is easily seen with the unaided eye, it is best seen
in a small telescope so you can see the ringed world in detail as it
vanishes behind the Moon. Saturn's moon Titan will be occulted before
Saturn, so you can see the Moon occult a moon.

SkippySky
predictions for cloud tomorrow around occultation time, it is best to
check closer to the event if you are intending to travel.

Weather is looking good for most of Australia, except Tasmania and perhaps Darwin.

If you are just watching with the unaided eye, Keep a close watch on the bright point that is Saturn above the Moon, you will see it suddenly "wink out" as it goes behind the dark edge of the Moon. It will be harder to see Saturn reappear from the bright side, but if you watch carefully you can see it slowly reappear.

In binoculars Saturn is a featureless oval, but it is big enough that you can see it slide behind the Moon rather than abruptly disappear. If you have a way to attach your binoculars to a tripod, this will make observing very easy. If not, use the back of a chair or some similar object to stabilise the binoculars, so that the image is not continuously swinging around.

Start watching about half an hour before
hand to get set up and familiar with the sky, earlier if you need to set up at telescope and get it aligned properly. This way you can watch the entire event
comfortably (trying to focus your telescope on Saturn moments before the
occultation will cause a lot of unnecessary stress). It is advisable to set up and practise on the Moon a day or so before
the event, so you are familiar with your telescope set-up. Tonight is a good time to practise with Mars close to the Moon.

The Moon is in its First Quarter phase, and it will be easier
to see Saturn as the glare of the Moon will not be so intense. On the
other hand picking up precisely when Saturn is about to reach the dark
edge of the Moon will be harder.

You don't need any fancy equipment to image this occultation, a mobile phone camera or a simple digital camera held over a telescope eyepiece will do it. I have a special device for holding the camera in place (available from all astro-optical stores, these images were taken with a point and shoot camera with this device) and there are telescope holders for iPads, but a simple camera held to the eyepiece will work (after some fiddling around to get the image into the camera lens).

But the first thing is to enjoy the occultation, worry about imaging it when you have had a good look.

Timings for major cities are shown below, nearby towns will have similar timing.

I'm on the Radio this Sunday August 3rd

In the morning (Sunday 3 August) I'll be on ABC local radio (Adelaide 891 AM) with Ashley Walsh , going live after 10:25 am ACST (10:55 AEST). I'll be talking about the upcoming occultation of Saturn, so listen if you can (they doing streaming, so even if you are not in Adelaide you can catch this on your computer).